Process for the preparation of hydrogenated hydrocarbon compounds

Abstract

A process for the dehydrogenation of a paraffinic hydrocarbon compound, such as an alkane or alkylaromatic hydrocarbon compound to produce an unsaturated hydrocarbon compound, such as an olefin or vinyl aromatic compound or mixture thereof, in which a dehydrogenation catalyst contacts gaseous reactant hydrocarbons in a reactor at dehydrogenation conditions.

The invention claimed is: 
     
       1. A process for dehydrogenating a hydrocarbon selected from at least one of:
 i) paraffinic hydrocarbons selected from ethane, propane, and butane; and 
 ii) alkylaromatic hydrocarbons selected from ethylbenzene, propylbenzene and methylethylbenzene; comprising 
 contacting a gaseous stream containing at least one of the hydrocarbons with a dehydrogenation catalyst comprising gallium and platinum and carried by an alumina or alumina silica support, at reaction temperature and in concurrent rising flow, at a catalyst to hydrocarbon ratio of 5 to 100 on a weight to weight basis, to a dehydrogenation reactor wherein the average contact time between the hydrocarbon and catalyst within the dehydrogenation reactor is from about 1 to about 4 seconds; and the temperature and pressure in the dehydrogenation reactor is from about 570 to about 750° C., and from about 6.0 to about 44.7 psia; and 
 transferring the hydrocarbon and catalyst from the dehydrogenation reactor to a two stage solid-gas impingement separator comprising a cyclone separation device wherein the average contact time between the hydrocarbon and catalyst while at reaction temperature in the separation device is less than about 5 seconds and the total average contact time between the hydrocarbon, catalyst and resulting hydrocarbons while at reaction temperature is less than about 10 seconds; and 
 transferring catalyst from the separation device to a regenerator where the catalyst is contacted with an oxygen-containing regeneration fluid and supplemental fuel. 
 
     
     
       2. The process of  claim 1  wherein the catalyst comprises an alkali or alkaline earth metal selected from at least one of: sodium, lithium, potassium, rubidium, magnesium, calcium, strontium and barium. 
     
     
       3. A process of  claim 1  wherein the catalyst has an average residence time within the dehydrogenation reactor from about 0.5 to about 40 seconds. 
     
     
       4. A process of  claim 1  wherein the dehydrogenation reactor is a riser reactor. 
     
     
       5. A process of  claim 1  wherein the dehydrogenation reactor is a fast fluidized reactor. 
     
     
       6. A process of  claim 1  wherein catalyst from the separation device is transferred to one of: a catalyst regenerator wherein the catalyst is regenerated and returned to the dehydrogenation reactor, and a recycle loop wherein catalyst is recycled from the separation device back to the dehydrogenation reactor. 
     
     
       7. A process of  claim 6  wherein the catalyst from the recycle loop and regenerator are combined and introduced into the dehydrogenation reactor.